Control for internal combustion engine



y 1959 F. c. DRUZYNSKI CONTROL FOR INTERNAL COMBUSTION ENGINE Filed Feb. 18, 1957 NQE hwxos KER; M26 2 w mm mm INVENTOR. FRANK C. DRUZYNSKI saiy 21% United States PatentO CONTROL FOR INTERNAL COMBUSTION ENGINE Frank C. Druzynski, Detroit, Mich., assignor to Continental Aviation & Engineering Corporation, Detroit, Mich., a corporation of Virginia Application February 18, 1957, Serial No. 640,650

8 Claims. (Cl. 123-140) My invention relates to controls for fuel injection type internal combustion engines and more particularly to a warm-up enrichment control for fuel injection systems.

As is well known to the art, internal combustion engines starting at low ambient temperatures generally require a much richer mixture during the warm-up period than when they are operating at their normal operating temperatures. This is presently accomplished on carburetorequipped engines through use of an automatic choke. However, fuel injection equipped engines heretofore have not been provided with such a control, as a result of which poor engine performance is experienced during warm-up periods, particularly in colder weather. Some means may be employed to hasten engine warm-up, but this is at best but a half measure.

An object of the present invention is to improve warmup performance of fuel injection type engines by providing a means for automatically enriching the fuel mixture while the engine is warming up.

Another object of the invention is to provide for fuel enrichment during the warm-up period of fuel injection engines by constructing a throttle inlet pressure line connected to the normal fuel injector pressure control and a means for closing the line when the engine warms up.

A further object of my invention is to improve fuel injection control during engine warm-up by providing a pressure operated injection system control having a throttle inlet pressure sensing control means adapted to be made gradually inoperative in response to a predetermined increase in engine operating temperatures.

For a more complete understanding of my invention, reference may be had to the accompanying drawing illustrating a preferred embodiment of the invention in which like characters refer to like parts throughout the several views and in which- Fig. 1 is a fragmentary side elevational view of a preferred fuel injection type internal combustion engine embodying my invention, and

Fig. 2 is a diagrammatic representation of the control system embodying the invention.

An internal combustion engine 10 is illustrated as having an air intake pipe 11 and a throttle valve 12 operable therein. A conventional fuel injection pump 13 is conveniently mounted on the engine 10 and is provided with a control mechanism 14, which is preferably operated by pressures taken from the air intake manifold 15 through a conduit 16, although, other pressure sources than intake manifold pressure may be utilized for such control.

A thermally actuated valve 17 is connected in temperature responsive relation to the engine 10, the connection in the engine shown being to a cooling system water jacket 18. Pressure conducting conduits 20 and 21 are connected from the valve 17 respectively to the air intake pipe 11 upstream of the throttle 'valve 12 and to the control mechanism 14.

As illustrated in Fig. 2, the control mechanism 14 preferably comprises a housing 25 having a pressure "ice control chamber 26. An actuating element such as a pressure responsive bellows 27 is supported in the chamber 26 and operates a pin 28 connected to the fuel injection pump 13 for regulating the amount of fuel material to the engine in a manner which is well known to one skilled in the art of fuel injection equipment andneed not be illustrated or described in detail here. For present purposes, it will be sufficient to note that in the preferred control mechanism shown, operation of the pin 28 to the right decreases the fuel flow to the engine to lean out the fuel/air mixture, and operation of the pin 28 to the left enriches the fuel/air mixture. Normal fuel control is achieved through actuation of the pin 28 by the bellows 27 in accordance with manifold air pressure, transmitted from the air intake manifold 15 through the conduit 16 to the control chamber 26.

The valve 17, connected between the pressure transmitting conduits 20 and 21, comprises a two-part valve housing 30 having an inlet port 31 and an outlet port 32 respectively communicating the conduits 20 and 21 with a valve chamber 33. A spring-loaded valve element 34 is supported in the chamber 33 and operably connected by means of a pin 35 to a thermal. responsive power element 36 of conventional construc: tion. The power element 36 has a chamber 37 filled with a material 38 having a substantially high coeflicient of thermal expansion, which serves to actuate the pin 35 outward upon application of heat to the power element 36, actuating the valve element 34 to close the port 31, interrupting pressure transmission from the air intake pipe 11 to the control mechanism 14. The power ele; ment 36 being connected to the water jacket 18, it will be sensitive to the temperature rise of the engine 10. Thus, at low ambient temperatures, when the cold engine 10 is being cranked over on the initial start, the pin 35 will be retracted to open the valve 34, bleeding throttle inlet pressure into the control chamber 26, actuating the pin 28 to the left, biasing the fuel injection system to a richer mixture position than would be had under manifold pressure control alone.

As the engine 10 warms up and the power element material 38 expands, sensing the increase in operating temperature, the pin 35 actuates the valve 34 to gradually close the port 31. Pressure in the control chamber 26 will correspondingly gradually drop to manifold pressure, actuating the pin 28 to the right, progressively leaning out the mixture, and when the port 31 is fully closed, the injection system will be restored to the normal operating position determined by the normal injection system control manifold pressure signal.

The power element 36 may be made responsive to any medium in the engine that will vary in temperature substantially in correspondence with variations of engine temperature, particularly during the initial warm-up period of the engine, depending on which type of medium serves best for the purpose. The drawing illustrates a preferred construction in which the power element 36 is connected with a water jacket. The temperature range in which the power element 36 opens and closes the valve port 31 may be controlled by the fill composition of the power element material 38. The rate of heat transfer into the power element 36 may be controlled by the design of the housing 30 and selection of materials from which the housing 30 is constructed. For example, a large valve body mass of low conductivity material will reduce the rate of heat transfer into the valve.

Although I have described but one preferred embodiment of my invention, it will be apparent to one skilled in the art to which the invention pertains that various changes and modifications may be made therein without departing from the spirit of the invention or the scope of the appended claims.

I- claim:

1. In an internal combustion engine having an air induction system, a throttle valve operable therein, and a fuel injection system including a fuel metering control means, a second means modifying the operation of said control means in response to pressuresin said air in duction system upstream of said throttle valve, and means constructed and arranged to inactivate the aforestiidsecond means in response to a predetermined increasein engine temperatures produced by and induced during engine operation.

2. In an internal combustion engine having an air induction system, a throttle valve operable therein, and a fuel injection system including a fuel metering control means, a second means modifying the operation of said control means in response to pressures in said air induction system upstream of said throttle valve, and means constructed and arranged to. progressively inactivate the aforesaid second means in response to a predetermined progressive increase in engine temperatures produced by and induced during engine operation.

3 In an internal combustion engine having an air induction system, a throttle valve operable therein, and a fuel injection system including a fuel injector and a pressure responsive control means therefor, said control means comprising a housing having a control chamber, actuating means in said control chamber and operable in response to pressure changes in same, a source of pressure varying in response to variable engine operating co ditions and connected with said control chamber, condu ,means openly connecting said control means with air induction, system upstream of said throttle valve, whereby to modify the operation of said injector control means, and means constructed and arranged for interrupting pressure flow through said conduit means in response to a predetermined increase in engine temperatures produced by and induced during engine operation.

4. In aninternal combustion engine having an air induction system, a throttle valve opfirabletherein, and a fuel injection system including a fuel injector and a pressure responsive control means therefor, said control means comprising a housing having a control chamber, actuating means in said control chamber and operable in response to pressure changes in same, a source of pressure varying in response to variable engine operating conditions and connected with said control chamber, conduit means openly connecting said control means with said air induction system upstream of said throttle valve whereby to modify the operation of said injector control means, and means constructed and arrangedto progressively interrupt pressure flow through said conduit. means in response to progressive increases in engine temperaturesproduced by and induced during engine operation, andto finally interrupt such pressure flow completely whenthe aforesaid engine temperature reaches'aselected predetermined value.

5. In an internal combustion engine, having an air induction system, a throttle valve operable therein, and a fuel injection system including a fuel injector and a pressure responsive control means therefor, said control means comprising a housing having a control chamber, actuating means in said control chamber and operable in response to pressure changes in same, a source of pressure varying in response to variable engine operating conditions and connected with said control chamber, 6

conduit; means openly connecting said control means with said air induction system upstream of said throttle valve, whereby to modify the operation of said injector control means, and means constructed and arranged for interrupting pressure flow through said conduit means in response to a predetermined increase in engine temperatures produced by and induced during engine operation, and comprising a valve disposed in said conduit means and operable to interrupt pressure flow through same, and a thermally expansive element-secured in heat transference relation to said engine and operatively connected to said valve for closing same in response to a predetermined increase of the aforesaid engine temperature.

6. In an internal combustion engine having a throttle air intake, an air intake manifold, 21 throttle valve associated therewith, and a fuel injection system including a pressure responsive control means actuated in response to manifold pressure changes, and a thermal responsive control means operable to selectively modify the effective manifold pressure changes in response to engine temperature changes below a selected predetermined value said engine temperature being produced by and induced during engine operation.

7. In an internal combustion engine having a' throttle air intake, an air intake manifold, a throttle valve associated therewith, and a fuel injection system including a pressure responsive control means actuated in response to manifold pressure changes, and a thermal responsive control means operable to selectively modify the effective manifold pressure changes in response to engine temperature changes below a selected predetermined value said engine temperature being produced by and induced during engine operation, said thermal responsive control means comprising pressure conducting means openly connecting said pressure responsive control means with said throttle air intake, a valve means associated with said pressure conducting means, and a thermal responsive actuator connected in heat transference relation with said engine and operable to selectively actuate said valve to close said conducting means in response to a selected predetermined increase in the aforesaid engine temperature.

8. In an internal combustion engine having a throttle air intake, an air intake manifold, a throttle valve associated therewith, and a fuel injection system including a pressure responsive control means actuated in response to manifold pressure changes, and a thermal responsive control means operable to selectively modify the effec tive manifold pressure changes in response to engine temperature. changes below a selected predetermined value said engine temperature being produced byv and induced during engine operation, said thermal responsive control means comprising pressure conducting means openly connecting said pressure responsive control means with said' throttle air intake, a valvemeans associated with said pressure conducting means, and'a therma'l responsive actuator connected in heattransference relation withsaid engine and operable to selectively actuate said valve to close said conducting means in response to a selected predetermined increase in the, aforesaid engine temperature, and thereby operative to only modify the effective manifold pressure changes below said selected predetermined value of the aforesaid engine temperature.

References Cited in the vfile of this. patent UNITED STATES PATENTS 2,447,267 Mock Aug. 17, 1948 

